"Please review the purpose of disbursement in question and provide clarification regarding its nature," reads the letter obtained by the Union-Tribune. "If the disbursement in question does indeed constitute personal use, the committee should seek reimbursement for the appropriate amount of the personal use violation from the beneficiary."

Rep. Duncan Hunter vaped during a hearing in Washington earlier this year. (Committee on Transportation and Infrastructure via Washington Po)

Hunter's camp said the congressman's 13-year-old son only used his dad's credit card for one game and claimed the other charges were not valid.

Joe Kasper, Hunter's chief of staff, told the Daily News in a statement that the congressman disclosed the charges before the FEC letter was sent, and "reimbursed for those charges." He also said there were unauthorized recurring charges.

"That's the issue and now it's between the credit card company and gaming platform," Kasper said.

If Hunter is blowing smoke, it's not the first time.

Rep. Duncan Hunter speaks during a news conference held by House Republicans. (Win McNamee/Getty Images)

Hunter stunned many people by vaping during a hearing in Washington in February. He was trying to block a ban on using e-cigarettes on airplanes.

Hunter has been a huge supporter of video games in the past, writing in Politico in 2013 that they are "often, but wrongly, identified as a catalyst for violence."

"Targeting video games as the problem is nothing more than a distraction from the broader challenges presented by improper parenting and far more obvious triggers of violence," he said.